What need a man forestall his date of grief,
And run to meet what he would most avoid?
Milton.

2.

To take possession of, in advance of some one or something else, to the exclusion or detriment of the latter; to get ahead of; to preoccupy; also, to exclude, hinder, or prevent, by prior occupation, or by measures taken in advance.

An ugly serpent which forestalled their way.
Fairfax.

But evermore those damsels did forestall
Their furious encounter.
Spenser.

To obstruct or stop up, as a way; to stop the passage of on highway; to intercept on the road, as goods on the way to market.

To forestall the market, to buy or contract for merchandise or provision on its way to market, with the intention of selling it again at a higher price; to dissuade persons from bringing their goods or provisions there; or to persuade them to enhance the price when there. This was an offense at law in England until 1844.